Airplane construction



Sept. 10, 1929. Q GIENGER 1,727,542

AIRPLANE CONSTRUCTION Filed March 13, 1929 Patented Sept. 10, 1929.

PATENT OFFICE.

ALBERT. CHARLES GIENGER, OF GHALOQUIN, OREGON.

AIRPLANE CONSTRUCTION.

Application filed March 13, 1929. Serial No. 346,696.

My invention relates to improvements in airplane construction, and itconsists in the combinations, constructions and arrangements hereinafterdescribed and claimed.

An object of my invention is to provide a new type of motive force forpropelling an airplane through the air, this force consisting of a unitcomprising a- Venturi tube, a propeller placed just in advance of thetube and having its blades extending a trifle beyond the rim of thetube, and a second propeller disposed inside of the rear of the tube andbeing rotated in a direction opposite to the first propeller. I haveshown two such units in the present application, although it is plbviousthat the number may be varied at w1 I have found that air will be forcedinto the tube by the leading propeller and will tend to spread outwardlyas it nears the end of the tube and to dissipate itself in differentdirections. The provision of the rear propeller has a tendency to causethe air issuing from the tube to be projected into the atmosphere in aline parallel with the longitudinal axis of the tube. I have found thatthis will result in an increased power.

Other objects and advantages will appear as the specification proceeds,and the novel features will be particularly pointed out in the appendedclaims.

My invention is illustrated in the accompanying drawing, in which Figure1 is a top plan view of the device;

Figure 2 is a front elevation; and

Figure 3 is a sectional view through a portion of the device. I

In carrying out my invention, I make use of an airplane indicatedgenerally at 1. On each side of the fuselage 2, I dispose one of theunits. It is obvious that the device can be attached to air craft ofatype different from that shown in Figure 1 without departing from thespirit and scope of the invention.

Each unit is identical, and therefore a description of one will suflice.In Figure 3 I show a Venturi tube 3 which is constructed of lightmaterial so as to reduce the weight to a mlnimum. The tube 3 is properlybraced,

59 as, for example, by struts 4.

Just in advance of the tube 3 I mount a propeller 5. This propeller iskeyed to a sleeve 6, and the latter is rotatably mounted upon a shaft 7.The shaft extends through the center of the tube 3, and is supported bybearings 8 and 9, the latter being carried by the fuselage 2.

The sleeve 6, has a pulley 10, and this pulley is connected to a pulley11 that is mounted upon the crank shaft 12 of the engine (not shown) Itwill be noted that the blade tips of the propeller 5 extend a slightdistance beyond the periphery of the tube 3.

A second propeller 13 is keyed to the shaft 7 and is disposed within thetube 3 near the rear end of the tube. A pulley 14 is keyed to the shaft7 and is connected to the pulley 11 by a belt 15 that is crossed over soas to cause the propeller 13 to rotate in a reverse direction to that ofthe propeller 5. I have shown belts 16 and 17 that lead to the otherunit for rotating similar propellers in this unit in the same manner asthat already described.

From the foregoing description of the various parts of the device, theoperation thereof may be readily understood. p

The forward propeller 5 causes air to be forced into the Venturi tube 3.This air will have a tendency to spread as it nears the end of the tube.The second propeller 13 strikes the air just as it is ready to spread,and prevents this spreading action and causes the air to be ejected in aline parallel with the longitudinal axis of the tube. Air issuing fromthe tube in a straight line with its axis has a greater propellingelfectthan air that is tending to spread as it leaves the tube. Thesecond propeller prevents small eddy currents which have a tendency tocut down the efficiency of the tube. The length of the tube depends uponthe pitch and the speed of the propellers.

The airplane to which the tubes are attached is controlled in the samemanner as a standard airplane. The device is simple in construction andis durable and efiicient for the purpose intended.

Although I have shown and described one embodiment of my invention, itis to be understood that the same is susceptible of various 2 mettlechanges, ancl I reserve the right to employ such changes as may comeWithin the scope of the invention as cleimeci.

ll claim:

5 1. A power means for airplanes enol the like comprising a tubularmember shaped like a venturi, means for forcing air into the front ofthe Venturi, and means dis oserl at the rear of the venturi for causingt' e air to be projected rearwardly in a stream that is parallel Withthe axis of the tube.

2. A motive power for air craft encl the like comprising at Venturitube, a propeller placed at the entrance oi the tube, at seconclpropeller placed at the rear of the tube, en i means for rotating saidpropellers in opposite directions.:

3. The combination with an airplane having it fuselage, of a, pair ofVenturi tubes,

2e one of the tubes being disposed on each siile of the fuselage,propellers mounted in the fronts oi? the tubes and having blades thatextencl e, slight distance beyond the rims of the tubes, and propellersdisposed in the rear ends or the tubes. 4. The combination with anairplane having a fuselage, of a pair of Venturi tubes, one of the tubesbeing disposed on each side of the fuselage, propellers mounted in theat fronts of the tubes and having blades that extend it slight distancebeyond the rims of the tubes, propellers disposecl in the rear endls ofthe tubes, and means for rotating the for Ward propellers in e directionopposite to the rear propellers.

5,. A motive power for vehicles comprising e Venturi tube, means forsucking air into the tubefor causing the air to converge with in thetube and then to tencl'to separate as it an nears the reer end. of thetube, and means disposec'i at the rear oi the tube for prevent ingdivergence of the for causing it to issue in straight stream is parall lthe ems oi the tube,

